Zooplankton abundance at three locations along the South east coast of Tamil Nadu near the Muthupet mangroves were investigated from July 2021 to June 2022. There were 72 zooplankton species found. Copepods, Foraminifera, Ciliata, Polychaetes, Chaetognatha, Cyclopoida, Rotifera, Cladoceran, Decapoda, Larva, Cumacea, and Tentaculata were the main zooplankton taxa found. The highest percentage was seen in Copepoda. It is clear from the biodiversity analysis that the Muthupet mangroves serve as a home for a diverse and rich zooplankton composition. This research may provide essential details for managing mangroves and protecting inshore habitats.